Internal combustion motor



Dec. 8, 931. D. E. CARPENTER 1,335,692

INTERNAL COMBUSTION MOTOR Filed Nov. 9. 1929 3 Sheets-Sheet l IN VENTOR.

ATTORNE S Dec. 8, 1931. 0.1:. CARPENTER 1,835,692

INTERNAL COMBUSTION MOTOR Filed Nov. 9. 1929 3 Sheets-Sheet 2 INVENTOR.7w. (3 BY ATTORNEY Dec. 8, 1931. D. E. CARPENTER 5,

INTERNAL COMBUSTION MOTOR Filed Nov. 9. 1929 s Shee t5$heet 5 iza(lvr/ab/c) [Mal/mi Va/Ve ope 27. IN VEN TOR.

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Aux/Mir m/ve By open. ATTORN S.

Patented Dec. 8, 1931 ran "raresrena FFIJCEI Davina. CARPENTER, orsrnm'err'snn, MASSACHUSETTS INTERNAL COMBUSTION Moron Application filedNovember 9, 1929. Serial No. 406,143.

motor is usable. .A furtheriobject isto secure v a greater power fromthe same displacement than has been possible with former constructions.These improvements are attained by a novel arrangementfor completelyscavenging the cylinder of exhaust gases and replacingthem by afreshcha'rge,so that a substantially undiluted fresh charge is presentat all throttle settings. .:The mechanism which I prefer. will bedescribed with particular reference to a usualfourfcycle internalcombustion motor. The invention is not restricted to this use, beingapplicable for example to theDiesel type. r

Referring to the drawings 1 v Fig. l is a sectionalview of airinternalusual water-jackets 11 and has running in it,

a piston 12 joined by a connecting rod 13 with a crank shaft 14. Abovethe piston the cylinder isenlarged to'provide the usual combastion space15, which extends sideways above the inlet valve 16 and the exhaustvalve l7. 'lhese valves are actuated'in the customai vmanner from cams18 and 19 respectively mounted on a cam shaft 20. A spark plug 21 alsoenters the combustion space to ignite the charge. 1 The parts as abovedescribed are substantially standard, andhave 5 therefore'not beenconsidered in detail;

combustion mot-or: embodying my invention According to my invention thecombustion space 15 extends beyondthe cylinder at the side remote fromthe inlet and exhaust valves so as to overlie an auxiliary chamber 22. A

' valve 23, shown as of the poppet type, provides an intermittentconnection between the auxiliary chamber and the combustion space. Thestem 24: of this valve extends downward ly through a spider guide 25 anda stuffing box 26, terminating outside the auxiliary chamber in a tappet27. Inside the chamber a the stem 24l is provided with a collar 28,between which and the spider 25, a spring 29 is compressed. The valve 23is opened. and

closed twice during each cycle of.tl1e motor,

. preferably by mechanism permitting a variance in the timing of oneofits actuations. The preferred form ofthis mechanism will now bedescribed. i

A hollow cam shaft 30 is arranged parallel to the cam shaft 20, and isconveniently driven from'the crank shaft 14 by gearing 31, 32. Thecamshaft 20 is'sim'ilarly driven from. the crank shaft by a gear33meshing with the gear Gears 32 and 33 are each twice the size of gear 31so that the cam shafts 20 and 30am rotated at a common speed which isone-half the speed of the crank shaft. lVithin the hollow cam shaft 30isa shaft 34L (Figs. 2, 3, and 4) through which passes transversely apin. 35. This pin extends. through opposite helical slots 36 in thehollow shaft 30 and preferably terminates in holes formed in a flangedcollar 37 slidably mounted on the cam shaft. A ring 38 is freely mountedupon the cylindrical portion of the collar, being confined between anintegral flange 39 of the latter and an opposed flange 40 which may bescrewedin place.

The ring 38 does not rotate, but is used merely for shifting the collarand the pin axially alongthe shaft. For this. purpose pins 41 aresecured tothe ring, fitting in yoke portions 42' of a shifting lever 43pivoted at 44 to a convenient point on the machine frame. As the lever43 is swung, the collar 38 will bemoved axially of the shaft, causingthe pin35 to traverse the helical slots 36. and cause relative rotativedisplacement between the hollow cam shaft and the inner shaft 34.

.The hollow cam shaft bears a cam port-ion 45 positioned to contact withthe tappet 27. A slot 46 is cut in the shaft 39 circu1nferentially inline with thecam prtio-n45, through which projects acam 47 secured as bya pin 48 within a recess in the central shaft 34. The two cam portionsa5 and Hare adapted to contact successively with the tappet 27 duringone cycle of the engine, the interval between their times of contactbeing adjust.

able through the mechanism which is controlled by arm 43.

V The functioningof the described mechanism will now be considered withspecial reference to Figs. 5 to 9 inclusive. Fig. 5 shows the motor atapproximately the time of ignition. The-inlet and'exhaust valves are ofcourse both closed, as is the auxiliary valve '23. The piston is causedto descend by the l pressure of the burning gases, and at about thebottom of the stroke the exhaust valve 17 opens as usual, remaining openduring the succeeding Lip-stroke so that the piston drives out most ofthe burnt gas from the cylinder.

Fig'. 6 shows thepiston approaching the end indi-catedthe' auxiliaryValve 23 opens, re-

y of the scavengingstroke. At about the point i l leasing ai -charge offresh which has been "confined within the chamber 22 ina manner c. to bedescribed. "This fresh gas travels across the combustion s ace-15,forcing the residual "burnt gas but the open exhaust valve port, andchar ing the combustion space with fresh undiluted gas. The exhaustand'auxihary a; valves then close. 7

On the succeeding downstroke of the piston; illustrated in Fig.7,..theinlet valve 16 is open an'dthe cylinder is charged with fresh'gas from the intake i'nanifo-ld. The inlet valve is closed," asusual,'at the termination of this down-stroke. During the fourth strokeofthe cycle the gas is compressed withj in the cylinder. It is duringthis latter stroke that the auxiliary valve is opened for the secondtime to introduce a portion of the charge into the chamber 22. Thepressure in the main cylinder of course varies progres- "sively fromsubatmospheric to the final compression prior to ignition. By varyingthe veriod during thisstroke at which the auxiliaty'valve is opened, thedegree of pressure fseifving to force the gas into the chamber 22 can bevaried. Thus, without changing the length of time during which valve 23is opened, it ispossible to vary the amount of charge placed in thechamber 22. The aux- 'iliar'y valve preferably closes before the pisanreaches its uppermost position, so that the higher degree of compressionis found only in the main cylinder.

dur'i' the suction stroke will vary; The less ch'arge' drawn in, theless the pressure at any given periodin 'the compression stroke.

"With varying degrees of throttle opening. the amount of charge drawninto the cylinder particular point in the travel of the piston whenthis'occurs, and if it is held open for a definite time in all settings,a substantially uniform charge will always be transferred to theauxiliary chamber.

The control of the variable cam 47 has been placed-priinarily-in thelever 43. This lever is preferably controlled from -the pressure in theintake'inanifold. T'oaccomplish this I have shown the lever-as joined bya link 50' with a bellows typ'e expansib'le and contractible member 51'of a usual construction, j oi ned by a'pipe' 52 with. the intakemanifold.

As the pressure i lithe-latter varies, as itwill with different throttlesettings or engine speeds, the cam mechanism will be adjustedautomatically to open the auxiliary valve at the proper time. Instead ofjoining the pipe to the intake in anifo'lchitcan be connected to oneofthe auXi-liary'chambers In this case the cam 47 willbe controlled by thepressure in the 'auxiliarly chamber rather than by the suction in theintake manifold. This is a nseful modi-fication where the variation in'theengine power is controlled by chang ing the timing of theinlet valveinstead of by a throttle, or where a supercharger is used.

What I claim is:

1. -Aninternal combustion motor of the type havinga cylinderprovided-with a piston and with inlet and exhaust ports, comprising aclosed auxiliary chamber and means for connecting theauxiliary chamberto the cvlinder once during the compression stroke of the-piston tocharge the chamber with fresh gas from the cylinder, and a'Ja'injustprior to the closure of theexhaust port wherebv the fresh gas from thechamber will replace the residual burned gas in the cylinder.

2. A four-cycle internal combustion motor of the type having a cylinderprovided with v a piston and with inlet'an'd exhaust valvescommunicating with the combustion space above the piston at a pointtoone side of the cylinder, comprising a closed auxiliary chamber andmeans for connecting the auxiliary chamber with the combustion space atthe opposlte side of the cylinder from the exhaust valve, said meansbein operative to es"ablish said connection once during the compressioni stroke to charge the auxiliary chamber with fresh gas from thecylinder,and

'llO

againjust prior tothe closure of'the exhaust valve whereby-the fresh"gas from the chum her will replace the residual burned-gas in thecombustion space.

3. An internal combustion motor of the type having a cylinder providedwith a piston and with inlet and exhaust ports, comprising an auxiliarychamber, means for connecting the auxiliary chamber to the. cylinderonce during the compression stroke of the piston to charge the chamberwith fresh gas, and again just prior to the closure of the ex haust portwhereby the fresh gas from the chamber will replace the'residual burnedgas in the cylinder, and means for controlling the portion of thecompression stroke during which the said connecting means is operative.

4. A four-cycle internal combustion motor of the type having a cylinderprovided with a piston and with inlet and exhaust valves communicatingwith the combustion space above the piston at a point to one side of thecylinder, comprising an auxiliary chamber, means for connecting theauxiliary chamber with the combustion space at the opposite side of thecylinder from the exhaust valve, said means being operative to establishsaid connection once during the compression stroke to charge theauxiliary chamber with fresh gas, and again just prior to the closure ofthe exhaust valve whereby the fresh gas from the chamber will replacethe residual burned gas in the combustion space, and means forcontrolling the portion of the compression stroke during which the saidconnecting means is operative.

5. An internal combustion motor of the type having a cylinder providedwith a piston and with inlet and exhaust ports, comprising an auxiliarychamber, means for connecting the auxiliary chamber to the cylinder onceduring the compression stroke of the piston to charge the chamber withfresh gas, and again just prior to the closure of the exhaust portwherebyv the fresh gas from the chamber will replace the residual burnedgas J in the cylinder, and means responsive to the pressure in theintake manifold for varying the portion of the compression stroke duringwhich the said connecting means is operative.

6. A four-cycle internal combustion motor of the type having a cylinderprovided with a piston and with inlet and exhaust valves communicatingwith the combustion space above the piston at a point to one side of thecylinder, comprising an auxiliary chamber, means for connecting theauxiliary chamber with the combustion space at the opposite side of thecylinder from the exhaust valve, said means being operative to establishsaid connection once during the compression stroke to charge theauxiliary chamber with fresh gas, and again just prior to the closure ofthe exhaust valve whereby the fresh. gas

from the chamber will replace the residual burned gas in the combustionspace, and means responsive to the pressure in the intake manifold forvarying the portion of the compression stroke during which the saidconnecting means is operative.

7. A four-cycle internal combustion motor of the type having a cylinderprovided with a piston and with inlet and exhaust valves communicatingwith the combustion space above the piston at a point to one side of thecylinder, comprising an auxiliary chamber, means for connecting theauxiliary chamber with the combustion space at the opposite side of thecylinder from the exhaust valve, said means being operative toestablishsaid connection once during the compression stroke to charge theauxiliary chamber with fresh gas, and again just prior to the closure ofthe exhaust valve whereby the fresh gas from the chamber will replacethe residual burned gas in the combustion space, and means for operatingsaid connecting means comprising a cam shaft making a complete rotationin each four strokes of the piston, a pair of cams carried by saidshaft, and means for varying the angular relationship between the camsduring the operation of the motor.

8. An internal combustion motor having a combustion chamber, a piston towhich power is supplied by the force of the combastion of gas in saidchamber and by which gas is compressed in the chamber preparatory toits'combustion, and means for removing a portion of the fresh gas fromthe combustion chamber during the compression phase and reintroducing itinto the chamber during the scavenging phase of the cycle.

9. A four-cycle internal combustion motor having a cylinder and pistondefining a combustion space between them, and means for removing aportion of the fresh gas from the combustion chamber during the.compression stroke of the piston and reintroducing such gas into thechamber at about the end of the scavenging stroke of the piston.

In testimony whereof I have aflixed my signature.

DAVID E- CARPENTER.

